What is a headphone amplifier, and do you need it?

A pair of wired headphones sitting on the surface of a table against the backdrop of engineering equipment.
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Are your headphones too quiet? Did you notice any noise or crackling when using headphones on a particular device? Headphone amplifiers may be exactly what you need.

What is a headphone amplifier?

Headphone amplifiers are low power amplifiers specifically designed for on-ear or in-ear listening devices. Available in all shapes and sizes, from integrated modules to standalone devices. Like standard hi-fi amps, most are solid state, but some use analog valves.

Monolith headphone amplifier

The device you’re using to read this article, whether it’s a smartphone or a notebook, may have a headphone amplifier. This type of amplifier is designed to drive most of the headphones known as low impedance headphones.

Why you need a headphone amplifier

If you are using headphones on a particular device and the volume is not loud enough, you can use a headphone amplifier to boost the signal and provide a higher output volume.

Related: Deafness: How big is it?

One of the reasons the headphones aren’t loud enough is that the built-in amplifier doesn’t provide enough power to drive the headphones. Most headphones are designed with an impedance of 50 ohms or less, which makes them easy to drive on most small devices such as smartphones and notebooks. The higher the impedance, the more power is required for the headphones.

Headphone sensitivity also has an effect. This is to determine the headphone volume (measured in decibels or dB) at a specific power level (measured in milliwatts or mW). When you buy headphones, these ratings are listed in the specifications, but most headphones have low impedance and are designed for use in everyday devices, so you can afford not to pay too much attention. ..

Comparison of sensitivity, power and impedance of Sennheiser headphones

High impedance headphones usually feature drivers that use thinner voice coils. Thinner coils are more difficult to manufacture because they use more wire layers than low impedance models. This means less air in the coil windings and stronger electromagnetic fields.

Such headphones (such as the Sennheiser HD 660 S) are “difficult” to drive because they are where headphone amplifiers are commonly used. As a result, it is widely believed that there is less distortion and better sound quality than the low impedance model. It’s not necessarily different from reading the instructions on the web, so it’s a good idea to go to a Hi-Fi retailer and see for yourself.

Sennheiser HD600S

High-end electrostatic headphones (sometimes called “ear speakers”) require an amplifier dedicated to that type of listening device. These headphones (such as the Mitchell and Johnson MJ1 and similar Stax models) use ultra-lightweight film instead of moving parts like common models that rely on electrocoils. They are widely considered the most natural and accurate headphones you can buy, but they aren’t cheap (especially when you take into account the price of a good amp).


In other words, if your headphones are loud enough and you’re not using a flashy in-ear monitor or over-ear headphones, you probably won’t. requirement Headphone amplifier.

If the headphones are too quiet, you need to match the sensitivity (measured in decibels) and impedance (measured in ohms) with the appropriate headphone amplifier.

Different types of headphone amplifier

The most common types of headphone amplifiers are integrated into most mobile devices such as MP3 players, smartphones and notebooks. They are designed to drive the most common types of headphones with impedances less than 50 ohms. Most models of headphones are large enough under these conditions.

Some devices, such as Apple’s 2021 16-inch and 14-inch MacBook Pro and some high-resolution portable audio players, can drive headphones with higher impedance, but this is not a rule, but an exception.

MacBook Jack and Port Close-up

There are also portable headphone amplifiers that are battery-powered and designed to provide louder output on the go. They may help drive the headphones with higher impedance, but they require additional space and battery power, which may be inconvenient. One example is the FiiOA3, which is suitable for driving headphones with an impedance of up to 150 ohms.

Portable headphone amplifier

Many headphone amplifiers not only boost the signal, but also act as an external digital-to-analog converter (DAC). These are useful if you find that the DAC built into the device is producing unwanted noise or interference. Some of these external DACs, like the NextDrive Spectra X, are ultra-portable and do not require an additional battery.

NextDrive Spectra-X

Then there are standalone headphone amplifiers designed for home listening, such as the iFiZENCAN designed for home listening. These should be combined with more expensive and high impedance over-ear headphones for a richer listening experience. They take up less space than the types of amplifiers used to drive speakers and are one of the most budget-friendly ways to take advantage of “audio fan” Hi-Fi equipment.


Finally, there are also headphone amplifiers designed for studio use with audio professionals in mind. These often allow multiple headphone sets to be connected to a balanced source, making them suitable for the production and mastering of music and other audio productions.

Wireless headphones do not require a separate amplifier

Wireless headphones and earphones already have built-in amplifiers and DACs. Most headphones of this type are purely wireless, so there is no place to “plug in” and receive the boosted signal.

Apple AirPods Pro

These headphones are designed with low power Bluetooth audio in mind. Audio signals often sacrifice audio quality in the name of convenience because the audio signal must be compressed before it can leave the device and reach the headphones wirelessly.

Wireless headphone amplifiers like the FiiO BTR3K exist, but they serve different purposes. These devices add Bluetooth capabilities to wired headphones and earphones and use a better DAC than most integrated models to further enhance the signal and improve digital-to-analog conversion.


You probably don’t need a headphone amplifier

Most headphones are designed for use with low power devices such as smartphones and portable audio players, so no signal boost is required. If your headphones are big enough for your listening habits, you probably don’t need them. If you’re using wireless headphones such as AirPods or similar Bluetooth models, you don’t need either.

If you’re looking for a unique audio experience, high-impedance headphones and a good amplifier are a great starting point. It’s a complete setup at a lower price than a set of high-end amplifiers and speakers, with fewer variables such as room acoustics.

But as we replace wires with wireless technologies like Bluetooth, more and more people are looking for convenience over sound quality. Check out our recommended wireless earphones for iPhone and iPad. If you’re not ready to cut the cord yet, we also have a list of the best headphones.

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